setcookie не работает!

include("connect.php");
$result=mysql_query("SELECT login,password FROM users");
while ($myrow=mysql_fetch_assoc($result)) {
    if ($_POST['login']==$myrow['login'] and $_POST['password']==$myrow['password']) {
        setcookie("log","AAA",time()+10);
        $_SESSION['userloggedin']=true;
        $_SESSION['login']=$myrow['login'];
        break;
    }
}
 
if ($_SESSION['userloggedin']!=true) {
    $_SESSION['mistace']="not_right_password";
    if ($_POST['login']) {$_SESSION['sentlogin']=$_POST['login'];}
    header("Location: ".$_SERVER['HTTP_REFERER']);
    exit();
} else {
    $_SESSION['mistace']="user_logged_in";
    if ($_SERVER['HTTP_REFERER']) {
        header("Location: ".$_SERVER['HTTP_REFERER']);
    } else {
        header("Location: ../index.php");
    }
    exit();
}

error_reporting(E_ALL);
include("connect.php");
$result=mysql_query("SELECT login,password FROM users");
while ($myrow=mysql_fetch_assoc($result)) {
        if ($_POST['login']==$myrow['login'] and $_POST['password']==$myrow['password']) {
                setcookie("log","AAA",time()+10);
                $_SESSION['userloggedin']=true;
                $_SESSION['login']=$myrow['login'];
                break;
        }
}
 
if ($_SESSION['userloggedin']!=true) {
        $_SESSION['mistace']="not_right_password";
        if ($_POST['login']) {$_SESSION['sentlogin']=$_POST['login'];}
        header("Location: ".$_SERVER['HTTP_REFERER']);
        exit();
} else {
        $_SESSION['mistace']="user_logged_in";
        if ($_SERVER['HTTP_REFERER']) {
                header("Location: ".$_SERVER['HTTP_REFERER']);
        } else {
                header("Location: ../index.php");
        }
        exit();
}

Warning: Cannot modify header information - headers already sent by (output started at Z:\home\localhost\www\curs\phpscripts\comein.php:8) in Z:\home\localhost\www\curs\phpscripts\comein.php on line 23

print_r($_COOKIE)

$result=mysql_query("SELECT password FROM users WHERE login='".$_POST['login']."'");

if ( mysql_num_rows ( $query ) == 1 ) {
//Продолжаем работу
}
else {
//Пользователь не найден
}

setcookie("log","AAA",time()+10, '/');

echo('<script language="JavaScript">
var dated = new Date(new Date().getTime() + 60*1000*60*24*365); //кука на год
document.cookie = "'.$name.'='.$value.'; path=/; expires=" + dated.toUTCString();
</script>');